PSI - Issue 37

Filipa G. Cunha et al. / Procedia Structural Integrity 37 (2022) 33–40 Filipa G. Cunha / Structural Integrity Procedia 00 (2022) 000–000

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• From the strain components evaluated across reference paths in the region of interest, it was observed, as expected, that the strains were greater in the upper part of the sample under the heat source deposition than region further away; • It is possible to observe that the largest strains occur in the layers underlying the new layers. The lower layers have practically no strains values. In this way, there is an expansion of the upper part of the sample. This phenomenon happens due to the application of a point heat source that heats the surface more, causing a surface expansion; • Preliminary results showed the feasibility of measuring in-situ DIC in WAAM process in order to determine the strain fields. Although the preliminary results had shown good feasibility of in situ DIC measurements during the WAAM process, there are still factors to be considered in further improvements: the use of a 3D-DIC (stereovision) system to take into account any out-of-plane movements that may occur on the wall sample during the layer deposition process; the use of a narrow bandpass optical filters on the cameras–lenses set-up; new ways of applying the speckle pattern avoid deterioration eventually caused by the local radiation of the WAAM process; the analysis of the process when manufacturing FGM parts produced by twin-wire WAAM process.

Acknowledgements

The authors acknowledge Fundac¸a˜o para a Cieˆncia e a Tecnologia (FCT-MCTES) thoughout the project UIDB / 00667 / 2020 (UNIDEMI). F.G. Cunha acknowledges the support of the Portuguese Fundac¸a˜o para a Cieˆncia e a Tecnologia under the grant 2021.06889.BD.

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